Wind motors have previously been proposed in which an assembly of several vanes rotates about a vertically oriented main shaft, with the additional vanes being disposed around the main shaft. Typical patents of this type include the following: T. O. Perry, U.S. Pat. Nos. 146,458, granted Jan. 20, 1874; F. McClintock, 256,234, patented Apr. 11, 1882; L. Royak, 1,844,796, granted Feb. 9, 1932, and G. Leon, 1,973,290, granted Sept. 11, 1934; C. F. Terhune, 2,247,929, granted July 1, 1941, and C. F. Terhune, 2,406,268, granted Aug. 20, 1946. These vertical axes, flat vane, wind energy converters date back to the last century and are so elaborate and complicated that they are rarely mentioned in current literature on the subject. One source of complication is the gearing or chains employed to rotatet each vane. Much additional needless complication of the early designs involve the inclusion of mechanical regulators to limit centrifugal forces during high winds. This idea was a carry-over from experience with radial vane systems which tend to self-destruct from centrifugal force in high winds. Propeller units, for example, often have tip speeds five or ten times greater than the wind velocity. However, speed regulation is not needed to protect flat vane vertical axis units because the vanes do not move faster than the wind. Calculations indicate that wind motor units of the present type will operate safely in winds over 100 miles per hour.
Most of the early patents show tail vanes, a feature which also indicates a misconception of the actual operation of the units. This is another carry-over from the inherently balanced radial vane systems which all used tail vanes to direct them into the wind. In the case of vertical axis flat vane wind converters, in the order of 60% of the torque tending to rotate the entire units about the central axis occurs on one side of the machine. Accordingly, even with a moderately large tail, the units will tend to shift in the order of 45 degrees or more from the optimum orientation relative to the wind, thereby decreasing the efficiency by a substantial factor, often in excess of 50%.
Most of the early arrangements used four, and some suggested using more than four vanes. However, the arrangements used by these early inventors for synchronously rotating the vanes were exceedingly complex and inefficient.
Accordingly, a principal object of the present invention is to provide an improved and simplified vertical axis flat vane type wind energy converter. A collateral object of the present invention is to provide a simple wind motor which may be employed to re-charge the automobile batteries of an electric car while the car is parked, either at night, or during the day while the owner is not using the car.